1. Field of the Invention
The present invention relates to an iris recognition system, and in particular to an iris recognition system which can extract an iris image of a user, by upwardly and downwardly rotating around a hinge bracket in order to be exactly rapidly controlled to a position of the user""s eyes.
2. Description of the Background Art
In an automatic access control system and an automatic commercial transaction system using an internet, the user""s biological characteristics have been recently utilized in order to identify the user. The biological characteristics are fingerprints, voice, retinas, faces, irises and the likes. Especially, every human being has different irises, and the irises are impossible to imitate and not varied for the entire life. Thus, the characteristics of the irises is applied to the systems, and used to identify the user.
Here, the iris implies a peripheral portion of a pupil of the animal""s eye. The iris is a muscle controlling opening/closing of the pupil, and serves to control an amount of light which is externally incident on eyeball.
In general, the human being""s eyes have been generally formed for the six months of pregnancy. Thereafter, a hole is formed at the pupil, and wrinkles are outwardly generated in a chaos pattern. The growth of the wrinkles is stopped within a few years after birth, and the wrinkles are not varied for the whole life. Accordingly, the iris including the wrinkles has its own pattern. Generally, the right iris of a person is different from the left iris of the person, and even identical twins have different irises as well.
Therefore, the iris recognition is to identify the shape of the iris having a specific pattern. That is, the irises photographed by a video camera are image-processed, and stored in a data base. Thereafter, a pattern of a currently-inputted iris is compared with that of the stored iris, thereby identifying the user having the currently-inputted iris.
An iris recognition system and a method thereof have been disclosed in the U.S. Pat. Nos. 4,641,349, 5,291,560 and 5,572,586.
Especially, the U.S. Pat. Nos. 4,641,349 and 5,291,560 relate to an iris imager for extracting an iris image, a system for analyzing the extracted iris image and an algorithm for generating an iris code of 256 bytes by using the iris image.
FIG. 1 is a cross-sectional view illustrating a conventional optical imager. As shown therein, the conventional optical imager includes: a camera 1 photographing eyes of the human beings, an optical lens 2 gathering light inputted to the camera 1, a light source unit 6 emitting light in order to photograph the eyes of the human beings, an LCD unit 4 displaying an image of the eyes of the user photographed by the camera 1, and a beam splitter 3 reflecting light incident from the eyes of the user to the camera 1, and passing an image of the eyes of the user incident from the LCD unit 4 toward the eyes of the user.
The conventional optical iris imager has a disadvantage in that a size of the system is large. In addition, the camera does not have an automatic zoom and focus function, and accordingly the user must directly focus on the camera at a predetermined distance.
As a result, it is difficult to focus the position and shape of the eyes of the user on the camera.
In addition, when the shape of the eyes of the user is photographed, a large amount of visible light is incident on the camera, and thus the image of the eyes cannot be exactly obtained.
Accordingly, the conventional optical iris imager has a low iris recognition rate.
A device for overcoming the aforementioned disadvantages has been described in the U.S. Pat. No. 5,572,596 (owned by Davio Sarnoff Research Center, Inc.). It uses an algorithm that traces his/her irises of the user.
However, although this system is convenient, three cameras for searching for the head and eyes of the human being and extracting the iris image, a device for controlling an angle of a mirror, and a plurality of high-power infrared light source units for lighting a peripheral region of the iris are necessary, thereby increasing the system size and cost.
Accordingly, it is a primary object of the present invention to provide a small-sized and low cost iris recognition system which can be easily operated, and which can exactly extract an iris image for a short time.
It is another object of the present invention to provide an iris recognition system which can extract an iris image of the user, by upwardly and downwardly rotating around a hinge bracket in order to be exactly rapidly controlled to a position of the user""s eyes.
In order to achieve the above-described objects of the present invention, there is provided an iris recognition system including, an optical imager obtaining an iris image of the user at an optimal state, an inner case at which the optical imager is disposed, an outer case supporting the inner case, and surrounding the surfaces of the inner case, except for the front surface thereof, a control unit receiving a signal outputted from the optical imager, and controlling the optical imager according to the signal, and a hinge bracket disposed at both side portions of the outer case, for supporting the inner case, and enabling the inner case to upwardly and downwardly rotate.